CVE-2026-23069: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix potential underflow in virtio_transport_get_credit() The credit calculation in virtio_transport_get_credit() uses unsigned arithmetic: ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); If the peer shrinks its advertised buffer (peer_buf_alloc) while bytes are in flight, the subtraction can underflow and produce a large positive value, potentially allowing more data to be queued than the peer can handle. Reuse virtio_transport_has_space() which already handles this case and add a comment to make it clear why we are doing that. [Stefano: use virtio_transport_has_space() instead of duplicating the code] [Stefano: tweak the commit message]

Affected products

• Linux Linux Kernel: from 4.8, before 6.1.162 (fixed in 6.1.162); from 6.2, before 6.6.122 (fixed in 6.6.122); from 6.7, before 6.12.68 (fixed in 6.12.68); from 6.13, before 6.18.8 (fixed in 6.18.8); version 6.19 only

Published 2026-02-04. Last modified 2026-06-17.